Why Won’t My Riding Mower Start?

By Lyle Weischwill | Mar. 31, 2022 5:46 am PST

There can be many reasons why your riding lawn mower won’t start — everything from a dead battery to interlock switch problems.

Try these basic troubleshooting steps to get your riding mower running again:

  • Charge or replace the battery. You won’t even hear the click of the starter solenoid as you turn the ignition key when the battery is dead. Charge the battery and see if the engine starts. If it does, then you know that the dead battery caused the starting failure. You’ll likely need to replace the battery if it won’t charge. If you replace the battery but it keeps going dead, then you may need to have a service technician replace the alternator.
  • Replace the gasoline in the tank. If the engine turns over but doesn’t start, bad gas could be causing the problem. In a well-ventilated area, drain the gasoline from the fuel tank and fill the tank with fresh gas.
  • Change the air filter. A clogged air filter won’t allow the engine to get enough air to start. Check the air filter and replace it if it’s dirty.
  • Check the spark plug. A dirty spark plug won’t ignite fuel in the engine cylinder. Pull the spark plug out and examine it. If the spark plug electrode is covered with black carbon deposits, replace the spark plug.

If these basic troubleshooting steps don’t help you get the riding mower started, then one of these more complicated failures could be preventing the engine from starting:

  • Blown fuse
  • Bad ignition switch
  • Failed safety interlock switch
  • Faulty starter solenoid
  • Bad starter motor
  • Broken ignition coil
  • Dirty carburetor
  • Clogged fuel filter

Although these are some of the most common failures that can prevent your riding mower engine from starting, more serious issues such as a cracked cylinder or seized piston can also keep the engine from starting.

If basic troubleshooting doesn’t fix the problem, have a service technician diagnose and repair your riding mower.

To prevent starting problems from happening, schedule riding mower maintenance by a technician yearly. Regular annual maintenance is important to make sure your riding mower stays in peak performance shape.

During riding mower maintenance, the service technician performs these services:

  • Inspect the engine’s air filter and recommend replacement if necessary.
  • Check the fuel filter for clogs.
  • Inspect the carburetor and recommend cleaning or replacement.
  • Check blade and drive belts for wear.
  • Lubricate moving parts.
  • Test the overall operation of the riding mower.

Having a service technician maintain your riding mower regularly will help it run smoother and last longer. Professional maintenance also helps prevent unexpected failures that could put your riding mower out of commission during the mowing season.

Enjoy the peace of mind that comes with keeping your riding mower in top shape with regular maintenance.